This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. n Phase I, we want to evaluate the robustness of SWIFT-LiTE sequence in 3T, comparing to SPACE and UTE. Such parameters as SAR, SNR, spatial resolution, scanning time, separation of short and long T2 components, and post-processing techniques will be evaluated at this stage. The ability to measure morphology with high precision (high isotropic resolution and high SNR within 10 minutes time window) will be the focus of Phase I. We expect to run 4 in vitro samples (1 bovine knee, 1 bovine spine and 2 human knee replacements) and 2 healthy human volunteers and 2 patients with knee injury. Each scan takes about 1.5 hours, totally 12 hours in 8 week-duration. The in vitro samples will also correlate with histology. In Phase II, we want to evaluate the 3d low SAR T1p relaxometry and T1p weighted image in vitro and in vivo. The comparison between traditional T1p and the new T1p will be evaluated on the objects. Special attention should be paid to SAR, and spatial resolution and scanning time. we expect to run 4 in vitro samples (1 bovine knee, 1 bovine spine and 2 human knee replacements) and 2 healthy human volunteers and 2 patients with knee injury. The in vitro samples will also correlated to 23Na imaging at 7T. Each scan takes about 1.5 hours, totally 12 hours in 8 week-duration. In Phase III, we want to evaluate gagCEST on 3D SPGE sequence from Siemens, Compared to our SWIFT-LiTE based gagCEST sequence and results from 7T scanner. Special attention should be paid to SNR, SAR, spatial resolution, and scanning time. we expect to run 2 in vitro samples (1 bovine knee, 1 bovine spine) and 1 healthy human volunteers and 1 patients with knee injury. The in vitro samples will also correlated to 23Na imaging at 7T. Each scan takes about 1.5 hours, totally 6 hours in 4 week-duration.